CN201485337U - Seawater desalination device with low pressure membrane separation method - Google Patents

Abstract

A seawater desalination device with a low-pressure membrane separation method, including a precision filter, a nanofiltration membrane separation device, a nanofiltration dialysis tank, a first-stage low-pressure reverse osmosis membrane system, a first-stage reverse osmosis dialysis tank, a second-stage low-pressure reverse osmosis membrane system, and a pump and the pipelines connecting each part; the precision filter is connected to the seawater delivery pump; then the nanofiltration membrane separation device is connected through the nanofiltration circulation pump, and the nanofiltration membrane dialysate pipeline is connected to the nanofiltration dialysis tank; The booster pump is connected to the first-level low-pressure reverse osmosis membrane system, the reverse osmosis membrane dialysate pipeline is connected to the first-level reverse osmosis dialysis tank, and the first-level reverse osmosis dialysis tank is connected to the second-level low-pressure reverse osmosis membrane system through the second-level reverse osmosis booster pump The second-level low-pressure reverse osmosis membrane concentrating pipe is connected to the nanofiltration dialysis tank; the first-level reverse osmosis dialysis tank is connected to the dialysate pipeline of the second-level low-pressure reverse osmosis membrane system through pipelines. Realize seawater desalination under low pressure, reduce the pressure resistance requirements and operation safety of the device, and reduce investment and operation energy consumption.

Description

Seawater desalination device with low pressure membrane separation method

technical field

The utility model relates to a seawater desalination device, in particular to a seawater desalination device with a low-pressure membrane separation method.

Background technique

Existing seawater desalination devices use seawater desalination membranes for one-step desalination after conventional pretreatment. Conventional pretreatment cannot completely remove impurities in seawater that affect the performance of desalination membranes. Therefore, a large flow rate is required to slow down the deposition of impurities on the membrane surface. One-step desalination needs to overcome high salt osmotic pressure. Large flow and high pressure make the device consume a lot of energy. Large-scale seawater desalination devices also need to be equipped with energy conversion devices. The equipment has the disadvantages of high operating pressure, high material requirements, high energy consumption, and poor safety.

Utility model content

The purpose of this utility model is to provide a low-pressure membrane separation seawater desalination device that uses a common membrane separation device to realize seawater desalination, reduce operating pressure, thereby reducing material requirements and energy consumption, and improving safety.

For achieving the above object, the solution of the present utility model is:

A low-pressure membrane separation seawater desalination device, which includes a precision filter, a nanofiltration membrane separation device, a nanofiltration dialysis tank, a first-stage low-pressure reverse osmosis membrane system, a first-stage reverse osmosis dialysis tank, a second-stage low-pressure reverse osmosis membrane system, The pump and the pipes connecting each part; the precision filter is connected to the seawater delivery pump; the precision filter is connected to the nanofiltration membrane separation device through the nanofiltration circulation pump, and the nanofiltration membrane dialysate pipeline is connected to the nanofiltration dialysis tank; the nanofiltration dialysis The tank is connected to the first-stage low-pressure reverse osmosis membrane system through the first-stage reverse osmosis booster pump, and the reverse osmosis membrane dialysate pipeline is connected to the first-stage reverse osmosis dialysis tank, and the first-stage reverse osmosis dialysis tank is passed through the second-stage reverse osmosis booster pump It is connected with the secondary low-pressure reverse osmosis membrane system, and the secondary low-pressure reverse osmosis membrane concentrating pipe is connected with the nanofiltration dialysis tank; the primary reverse osmosis dialysis tank is connected with the dialysate pipeline of the secondary low-pressure reverse osmosis membrane system through pipelines.

After adopting the above-mentioned scheme, the seawater desalination device of the present utility model adopts nanofiltration as the pretreatment of reverse osmosis desalination functionally, thereby removing all factors affecting reverse osmosis desalination, and the membrane surface flow rate is only related to the set water recovery rate , the flow rate is greatly reduced, thereby reducing energy consumption; in principle, using the rejection rate of different membranes, the total osmotic pressure of the salt is balanced with the water production efficiency of the membranes at all levels, and each membrane level shares part of the osmotic pressure of the salt, Lowering the operating pressure of the unit to conventional pressure values further reduces energy consumption and eliminates the need for an energy recovery unit.

This device realizes the seawater pretreatment and the three-stage membrane separation device respectively bear part of the osmotic pressure of the salt solution in seawater, realizes seawater desalination under low pressure, thereby reducing the pressure resistance requirements and operation safety of the device, and reducing investment and operation capacity consumption.

Description of drawings

Fig. 1 is a schematic diagram of the seawater desalination device of the present invention.

Detailed ways

As shown in Fig. 1, the low-pressure membrane separation method seawater desalination device of the present utility model comprises a seawater delivery pump 1, a precision filter 2, a nanofiltration circulation pump 3, a nanofiltration membrane separation device 4, a nanofiltration dialysis tank 5, a Stage reverse osmosis pressurized pump 6, stage 1 low-pressure reverse osmosis membrane system 7, stage 1 reverse osmosis dialysis tank 8, stage 2 reverse osmosis pressurized pump 9, stage 2 low-pressure reverse osmosis membrane system 10 and pipelines 11 connecting various parts composition. Seawater delivery pump 1 is connected to precision filter 2 by pipeline 11 to deliver seawater to precision filter 2; nanofiltration circulation pump 3 is respectively connected to precision filter 2 and nanofiltration membrane separation device 4 through pipeline 11, and nanofiltration membrane dialysis The liquid pipeline 41 is connected to the nanofiltration dialysis tank 5, and the nanofiltration dialysis tank 5 is connected to the first-level low-pressure reverse osmosis membrane system 7 through the first-level reverse osmosis booster pump 6 and the pipeline 11, and its reverse osmosis membrane dialysate pipeline 71 is connected to On the primary reverse osmosis dialysis tank 8, the primary reverse osmosis dialysis tank 8 is connected to the secondary low pressure reverse osmosis membrane system 10 through the secondary reverse osmosis booster pump 9 and the pipeline 11, and the secondary low pressure reverse osmosis membrane concentrating pipe 101 is connected to the nano The filter dialysis tank 5 is connected; the primary reverse osmosis dialysis tank 8 is connected with the dialysate pipeline 102 of the secondary low-pressure reverse osmosis membrane system 10 through a pipeline 11 .

The working principle of the device is: the seawater delivery pump 1 transports the seawater to the precision filter 2, removes impurities that affect the operating parameters of the nanofiltration, so that the quality of the seawater meets the inlet conditions of the nanofiltration; The seawater is transported to the nanofiltration membrane separation device 4, part of the intercepted concentrated seawater is discharged, and part of it is returned to the nanofiltration membrane separation device 4 through the nanofiltration circulation pump 3, so as to increase the membrane surface flow rate and ensure that the trapped impurities do not stay on the membrane surface. Membrane separation performance. The nanofiltration membrane dialysate enters the nanofiltration dialysis tank 5 through the nanofiltration membrane dialysate pipeline 41, and the nanofiltration dialysis seawater is transported to the first-stage low-pressure reverse osmosis membrane system 7 through the first-stage reverse osmosis booster pump 6, so that some low-cost The salt is intercepted, the intercepted concentrated solution is discharged, and enters the primary reverse osmosis dialysis tank 8 through saline seawater, and then is transported to the secondary reverse osmosis membrane system 10 by the secondary reverse osmosis booster pump 9, and the concentrated solution is returned to the In the nanofiltration dialysis tank 5, the dialysate reaches the salt standard of tap water.

Functionally, the seawater desalination device of the present invention adopts nanofiltration as the pretreatment of reverse osmosis desalination, thereby removing all factors affecting reverse osmosis desalination, the flow rate of the membrane surface is only related to the set water recovery rate, and the flow rate is greatly reduced , so as to reduce energy consumption; in principle, use the rejection rate of different membranes to balance the total osmotic pressure of salt with the water production efficiency of membranes at all levels, and share part of the osmotic pressure of salt with each membrane level, so that the operating pressure of the device will drop to conventional pressure values, further reducing energy consumption, thereby eliminating the need for energy recovery devices.

It can be seen that this device realizes the seawater pretreatment and the three-stage membrane separation device respectively bear part of the osmotic pressure of the saline solution in seawater, and realizes desalination of seawater under low pressure, thus reducing the pressure resistance requirements and operating safety of the device, reducing the investment and operating energy consumption.

The key of the utility model is:

1. The nanofiltration membrane device is used as the pretreatment of the reverse osmosis desalination device.

2. Nanofiltration and two-stage reverse osmosis balance the total osmotic pressure of seawater desalination, thereby realizing seawater desalination with low pressure.

3. The influent flow rate of two-stage reverse osmosis is only related to the water recovery rate.

Claims (1)

1. a low-pressure membrane partition method sea water desalinating plant is characterized in that: comprise accurate filter, nanofiltration membrane separation device, nanofiltration dialysate tank, one-level low pressure reverse osmosis film system, first-stage reverse osmosis dialysate tank, secondary low pressure reverse osmosis film system, pump and be connected each pipeline partly; Accurate filter connects the seawater transferpump; Accurate filter connects the nanofiltration membrane separation device by the nanofiltration recycle pump again, and nanofiltration membrane dialyzate pipe connection is to the nanofiltration dialysate tank; The nanofiltration dialysate tank links to each other with one-level low pressure reverse osmosis film system by the first-stage reverse osmosis force (forcing) pump, its reverse osmosis membrane dialyzate pipe connection is to the first-stage reverse osmosis dialysate tank, the first-stage reverse osmosis dialysate tank links to each other with secondary low pressure reverse osmosis film system by the two-pass reverse osmosis force (forcing) pump, and secondary low pressure reverse osmosis membrane concentration pipe links to each other with the nanofiltration dialysate tank; The first-stage reverse osmosis dialysate tank links to each other with secondary low pressure reverse osmosis film system dialyzate pipeline by pipeline.

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